Base support for wind-driven power generators

ABSTRACT

Disclosed are apparatus and corresponding methodology for providing a base support, such as including concrete, and used such as for a wind-driven generator. Precast concrete cylinders are stacked in place upon a platform that may be partially precast and partially cast in place during assembly and supported, in certain embodiments, by plural concrete legs, the other ends of which are supported on a unitary or subdivided concrete foundation. In other embodiments, the platform may be supported by ribbed concrete panels. The concrete cylinders are glued together using an epoxy and then secured by an internal vertical post tension system extending from the platform to the upper most cylinder. Different types of concrete are used between upper and lower sections of the stacked cylinders. The lower section uses reinforced concrete while the upper section used ultra high performance fiber reinforced concrete.

PRIORITY CLAIM

This application claims the benefit of previously filed U.S. PatentApplication entitled “METHODS FOR CONSTRUCTING A BASE STRUCTURE FOR ASUPPORT TOWER,” assigned U.S. Ser. No. 13/658,358, filed Oct. 23, 2012;and claims the benefit of previously filed U.S. Patent Applicationentitled “CONCRETE BASE SUPPORT FOR WIND-DRIVEN POWER GENERATORS,”assigned U.S. Ser. No. 12/482,634, filed Jun. 11, 2009; and claims thebenefit of previously filed U.S. Provisional Patent Application entitled“CONCRETE BASE SUPPORT FOR WIND-DRIVEN POWER GENERATORS,” assigned U.S.Ser. No. 61/061,173, filed Jun. 13, 2008; and claims the benefit ofpreviously filed U.S. Provisional Patent Application entitled “BASESUPPORT FOR WIND-DRIVEN POWER GENERATORS,” assigned U.S. Ser. No.61/113,354, filed Nov. 11, 2008; and claims the benefit of previouslyfiled U.S. Provisional Patent Application entitled “BASE SUPPORT FORWIND-DRIVEN POWER GENERATORS,” assigned U.S. Ser. No. 61/143,460, filedJan. 9, 2009; and claims the benefit of previously filed U.S.Provisional Pat. Application entitled “BASE SUPPORT FOR WIND-DRIVENPOWER GENERATORS,” assigned U.S. Ser. No. 61/171,965, filed Apr. 23,2009; and claims the benefit of previously filed U.S. Provisional PatentApplication entitled “METHOD AND APPARATUS FOR FABRICATION OF STRUCTURESUSED IN CONSTRUCTION OF TOWER BASE SUPPORTS,” assigned 61/174,700, filedMay 1, 2009; all of which are fully incorporated herein by reference forall purposes.

FIELD OF THE INVENTION

The present subject matter relates to towers. More specifically, thepresent subject matter relates to tower construction and methodologiesfor assembly, such as may be provided involving precast concrete andused in conjunction with dynamic structures such as wind-driven powergenerators or windmills.

BACKGROUND OF THE INVENTION

Construction of towers for support of various items has been practicedfor many years. Various towers of various materials have been providedto support electrical transmission lines including wooden, steel, and,more recently, concrete. In like manner, wind driven apparatus includingwindmills and wind-driven power generators in various forms and designedfor many purposes, including pumping of water from wells as well as,more recently, generation of electrical power, have also been developed.

U.S. Pat. No. 3,793,794 to Archer et al. entitled “Stacked Column” isdirected to a column comprised of a plurality of concrete-filled stackedtubes.

U.S. Pat. No. 4,406,094 to Hempel et al. entitled “Apparatus forAnchoring Self-supporting, Tall Structures” is directed to an anchoringself-supporting tall structure such as masts, towers, or the like in afoundation. The mast or tower may be used to support a wind-driven powergenerator.

U.S. Pat. No. 5,761,875 to Oliphant et al. entitled “Reinforced concretePole with Attachment Mechanism” is directed to an attachment mechanismwhich provides a structurally sound means to attach a reinforcedconcrete pole to a support structure.

U.S. Pat. No. 6,532,700 to Maliszewski et al. entitled “Flange With CutFor Wind Tower” is directed to a flange for making a tower for a windgenerator made up of a plurality of cylindrical steel segments.

U.S. Pat. No. 7,155,875 to Henderson entitled “Method of Forming aPerimeter Weighted Foundation For Wind Turbines And The Like” isdirected to a weighted foundation having a central pier pedestal and anenlarged base space outwardly and extending below the pedestal.

U.S. Pat. No. 5,586,417 to Henderson, et al. entitled “Tensionless pierfoundation” is directed to a hollow, cylindrical pier foundation isconstructed of cementitious material poured in situ between inner andouter cylindrical corrugated metal pipe shells.

The disclosures of all the patents referenced herein are incorporated byreference, for all purposes.

In an article entitled “Precast concrete elements for wind powerindustry,” German company Enercon GmbH has described methodology forcasting concrete. Mexican company Postensa Wind Structures describes onits website www.postensaws.com a tilt up, precast on-site constructionsystem for concrete towers for use with wind driven power generators.

While various implementations of tower constructions have beendeveloped, and while various combinations of materials have beenemployed for tower construction, no design has emerged that generallyencompasses all of the desired characteristics as hereafter presented inaccordance with the subject technology.

SUMMARY OF THE INVENTION

In view of the recognized features encountered in the prior art andaddressed by the present subject matter, improved apparatus andmethodology are presently disclosed for providing base supports forwindmills and wind-driven power generators (e.g., wind turbines). Itshould be appreciated that while the present disclosure is directed inexemplary fashion to support structure involving precast concrete,various presently disclosed constructions may be alternatively practicedin accordance with the present subject matter.

In addition, it should be appreciated that while the present disclosureis directed in exemplary fashion to support structure for windmills andsimilar devices, such is not necessarily a specific limitation of thepresent subject matter. For example, it should be clear to those ofordinary skill in the art that a tower constructed in accordance withthe present technology may well be used to support, for example, atelevision transmitter aerial or other radio signal broadcasting aerial.Alternatively, towers constructed in accordance with present technologymay be used to support any type device that may require placement abovelocal ground level for more effective operation. Such other present usesmay include, for example, such as electrical power transmission linesand athletic field lighting equipment.

In one exemplary configuration, support for windmills may be provided bystacking on-site a plurality of precast concrete cylinders to form aself-supporting tower.

In one of its simpler forms, a first number of the precast concretecylinders may be provided as reinforced prestressed concrete while asecond number of the precast concrete cylinders may be provided as ultrahigh performance fiber reinforced concrete.

Another positive aspect of one example of the present type ofconstruction is that the precast concrete cylinders may be assembledupon a raised platform supported by a plurality of precast concretelegs, each of which may me supported on individual concrete foundationblocks positioned below local ground level.

In accordance with aspects of certain embodiments of the present subjectmatter, methodologies are provided to secure individual precast concretecylinders together using adhesives.

In accordance with certain aspects of other embodiments of the presentsubject matter, methodologies have been developed to provide a temporarysupport for a raised platform.

In accordance with yet additional aspects of further embodiments of thepresent subject matter, apparatus and accompanying methodologies havebeen developed to provide an internal vertical post tensioning systemwithin the stacked concrete cylinders to maintain structural integrityof the stacked assembly.

In accordance with yet further embodiments of the present subjectmatter, a ribbed concrete block structure may be provided as analternative support for a raised tower supporting platform.

In yet still further alternative embodiments of the present subjectmatter, a tower supporting platform may correspond in part to a precastportion and a field poured portion.

In accordance with further embodiments of the present subject matter, apoured-in-place concrete circular strip footing may be providedrequiring little or no excavation.

In accordance with aspects of certain exemplary embodiments, a conicalskirt may be provided to distribute the tower load to the foundation.

In accordance with yet further aspects of certain exemplary embodimentsof the present subject matter the foundation could be precast and castmonolithically with vertical stave elements.

In accordance with yet still further aspects of certain exemplaryembodiments, the foundation may be configured to add additional deadload by means of external ballasts.

One exemplary embodiment of the present subject matter relates to a basestructure for a support tower, comprising a ring foundation pad; atransition piece disposed above such ring foundation pad; and aplurality of staves positioned around such transition piece, each ofsuch plurality of staves respectively comprising a top portion and abottom portion, the bottom portion of each such stave being wider thanthe top portion of each such stave. In such an arrangement, preferablysuch bottom portion of each such stave may be respectively secured tosuch ring foundation pad and such top portion of each such stave may berespectively secured to such transition piece. Such plurality of stavesand such transition piece may be constructed primarily of concrete.

In variations of the foregoing, such base structure may further includea plurality of anchor elements, located on such ring foundation pad, andrespectively configured to secure one of such staves against radial andlateral movement. Still further, optionally, each of such plurality ofanchor structures includes a receiving conduit, adapted to receive atendon threaded through one of such plurality of staves; and each ofsuch plurality of staves includes at least one conduit extendingtherethrough, with at least one tendon extending through such conduit.

In other present alternatives, such base structure may further include acentral foundation pad situated within such ring foundation pad; and atower structure supported on such central foundation pad, with suchtransition piece positioned on top of such tower structure. Also, suchtransition piece may include a plurality of facets around a perimeterthereof; and such top portion of each such stave may be configured to berespectively adhered to one of such plurality of facets. Such transitionpiece optionally may further define an aperture formed through a centralportion thereof. In some instances, such aperture may have an ellipticalshape.

In certain present variations, each of such plurality of staves mayinclude at least one conduit extending through such stave and at leastone tendon extending through such conduit. Optionally, such conduit maybe a U-shaped conduit extending partially through such stave. Further,such conduit may be a U-shaped conduit comprising first and second legsconnected by a horizontal portion, such first leg of such U-shapedconduit extending through a first stave of such plurality of staves andsuch second leg of such U-shaped conduit extending through a secondstave of such plurality of staves. Such horizontal portion of suchU-shaped conduit may extend across a plurality of staves.

Per present additional variations, such ring foundation pad may beconstructed of a plurality of foundation sections; and such plurality offoundation sections may be secured together by a metallic strandthreaded through such plurality of foundation sections.

In other present alternatives, such transition piece may comprise acentral ring structure; and such base structure may be a multi-stagedbase structure comprising an upper transition piece disposed above suchcentral ring structure; and a plurality of upper staves surrounding suchupper transition piece, each such upper stave respectively comprising atop portion and a lower portion, the bottom portion of each such upperstave being wider than the top portion of each such upper stave, andwith such lower portion of each such upper stave being secured to suchcentral ring structure and such upper portion thereof being secured tosuch upper transition piece.

In some present exemplary base structure arrangements, such basestructure may comprise a plurality of tubular structures stacked on topof such transition piece; and such plurality of tubular structures maybe constructed primarily of concrete. In certain of such arrangements,each of such plurality of tubular structures may include a conduitextending therethrough; and such base structure may further include atleast one tendon threaded through such conduit of such tubular structureand through a conduit located in one of such plurality of staves, forsecuring such tubular structure to such transition piece.

Another present exemplary embodiment relates to a support tower,preferably comprising a foundation; a base structure secured to suchfoundation; a transition piece secured to such base structure; aplurality of tubular structures stacked on top of such transition piece,each such tubular structure defining a hollow opening; such plurality oftubular structures including a topmost tubular structure having alocking mechanism; and a mast section having a bottom end and a top endinserted through such hollow openings of such plurality of stackedtubular structures, such mast section being movable between respectivefirst and second positions thereof. In such arrangement, preferably suchmast section may be configured to be secured in such second positionthereof by engaging such bottom end of such mast section with suchlocking mechanism.

Optionally, in such arrangement, such transition piece may comprise anelliptical aperture. Further optionally, such support structure mayfurther include a metallic plate covering such elliptical aperture, suchmetallic plate being removable through such elliptical aperture of suchtransition piece. Such metallic plate may have a plurality of standoffsextending from a top surface thereof, and such support tower may furtherinclude a lifting plate. Such lifting plate optionally may include asealing ring around an outer perimeter thereof. In other presentalternatives, such lifting plate may include a plurality of pedestalsextending from such lifting plate; and such mast section may be in suchfirst position thereof when such bottom end of such mast section may beresting on such pedestals of such lifting plate.

Per further present options, such locking mechanism of such topmosttubular structure may include an initial ring precast into such topmosttubular structure, such initial ring having a plurality of supportteeth; and a toothed ring positioned above such initial ring, suchtoothed ring comprising a plurality of locking teeth. Still further,such bottom end of such mast section may comprise a toothed ring lockingmechanism, with such toothed ring locking mechanism comprising aplurality of ring teeth; such plurality of support teeth and suchplurality of locking teeth may comprise a ramped surface to providefrictional engagement with such ring teeth of such toothed ring lockingmechanism; and such mast section may be in such second position thereofwhen such ring teeth of such toothed ring locking mechanism may be at anelevation between such support teeth and such locking teeth. Also, suchmast section may be configured to be secured in such second position byrotating such mast such that such ring teeth engage such support teethand such locking teeth.

Variations of the foregoing may include securing a wind turbine to suchtop end of such mast section. Such mast section may include acylindrical steel section. Also, optionally, such transition piece, suchbase support, and such plurality of stacked tubular structures may beconstructed primarily of concrete.

Per another exemplary embodiment of the present subject matter, asupport tower may comprise a foundation having an outer perimeterdefining a foundational footprint; a base structure having respectivetop and bottom potions, with such bottom portion thereof secured to suchfoundation; a transition piece associated with such top portion of suchbase structure such that such transition piece may be in a state ofhorizontal axis compression; and a mast section, having an outerperimeter defining a mast footprint smaller than such foundationalfootprint, and associated with such transition piece such that suchtransition piece may be in a state of vertical axis compression. In sucharrangement, preferably such transition piece may be configured toreceive poured material to fix such horizontal and vertical axescompressions thereof.

In the foregoing exemplary support tower, optional features may includeproviding such foundation as a ring foundation constructed primarily ofconcrete; and including poured concrete in such transition piece to fixsuch horizontal and vertical axes compressions thereof. Also optionally,such foundation may comprise a plurality of peripheral foundation padsconstructed primarily of concrete; and such transition piece may includepoured concrete to fix such horizontal and vertical axes compressionsthereof. Such base support structure may comprise a plurality of legs,each of such legs constructed primarily of concrete, and having a firstend respectively secured to such foundation and second end respectivelysecured to such transition piece. Alternatively, such base supportstructure may comprise a plurality of staves, each of such stavesconstructed primarily of concrete, and having a top portion and a bottomportion, the bottom portion of each such stave being wider than the topportion of each such stave, such bottom portion of each such stave beingsecured to such foundation and such top portion being secured to suchtransition piece.

Per other present variations, such mast structure may include aplurality of stacked tubular structures constructed primarily ofconcrete, and configured to support a wind turbine generator; and suchtransition piece may be constructed primarily of concrete. An exemplarysuch support tower may further include a plurality of post-tensioningcables, extending through such base structure and such mast structure,and circumferentially around such transition piece, and configured so asto respectively provide vertical and horizontal compressions to suchtransition piece.

Other variations may be practiced. For example, such support tower mayfurther include a central foundation pad and a tower structurecomprising an access ladder, and extending from such central foundationpad, such transition piece being located on top of such tower structure.Such tower structure may be constructed primarily from concrete. Suchtower structure may have a cruciform cross-section, or other.

It may be to be understood by those of ordinary skill in the art fromthe disclosure herewith that the present subject matter equally relatesto both methodology as well as apparatus subject matter. One exemplarypresent method relates to a method for constructing a base structure fora support tower, comprising constructing a ring foundation pad;positioning a transition piece above such ring foundation pad;positioning a plurality of staves around such transition piece, each ofsuch plurality of staves respectively comprising a top portion and abottom portion, such bottom portion of each such stave being wider thansuch top portion thereof; respectively securing such bottom portion ofeach of such plurality of staves to such ring foundation pad; andrespectively securing such top portion of each of such plurality ofstaves to such transition piece. In some of such exemplary practices,such plurality of staves and such transition piece may be constructedprimarily of concrete.

Per other present alternatives, such method may optionally furtherinclude constructing a central foundation pad situated within such ringfoundation pad; supporting a tower structure on such central foundationpad; and positioning such transition piece on top of such towerstructure. Alternatively, such method may even further include removingsuch tower structure after such plurality of staves have been secured tosuch transition piece.

Per other present variations, such method may further include providingsuch transition piece with a plurality of facets defined about aperimeter thereof; and respectively securing such top portion of eachsuch stave to respective facets defined on the perimeter of suchtransition piece. Also, such transition piece may further define anaperture formed through a central portion thereof. In some instances,such aperture may have an elliptical shape.

In other present variations, such method may further include selectivelyincluding conduits in such plurality of staves; extending at least onetendon through a conduit disposed in one of such plurality of staves;and applying tension to such at least one tendon to secure such stave tosuch base structure. Such conduit may extend through the length of suchstave. Such conduit may be a U-shaped conduit extending partiallythrough the length of such stave. Still further, such conduit maycomprise a U-shaped conduit having respective first and second legsconnected by a horizontal portion, wherein such first leg extendsthrough a first stave of such plurality of staves and such second legextends through a second stave of such plurality of staves.

Per present alternatives, such step of constructing a ring foundationpad may include providing a plurality of foundation sections; placingsuch plurality of foundation sections together to form such ringfoundation pad; and threading a metallic stand through such plurality offoundation sections to secure such plurality of foundation sectionstogether. In some instances, such method may further include providing aplurality of anchor elements located on such ring foundation pad; andrespectively securing such bottom portion of each such stave to one ofsuch plurality of anchor elements on such ring foundation pad, forsecuring such plurality of staves against radial and lateral movement.Still further may be included threading at least one tendon through oneof such plurality of staves; threading such tendon through a receivingconduit of such anchor structure; and applying tension to such tendon tosecure such stave to such anchor structure.

The subject method may practice alternative arrangements per presentsubject matter. For example, such transition piece may comprise acentral ring structure; and such method may further include constructinga multi-staged base-structure by positioning an upper transition pieceabove such central ring structure; positioning a plurality of upperstaves around such upper transition piece, each of such plurality ofupper staves respectively comprising a top portion and a bottom portion,with such bottom portion of each such upper stave being wider than suchtop portion thereof securing such bottom portion of each of suchplurality of upper staves to such central ring structure; and securingsuch top portion of each of such plurality of staves to such uppertransition piece.

Present methodology optionally may further include stacking on top ofsuch transition piece a plurality of tubular structures constructedprimarily of concrete. Also, such method optionally may further includeproviding a conduit respectively extending through each of suchplurality of tubular structures; threading at least one tendon throughsuch conduit of such tubular structure; threading such tendon throughone of such plurality of staves; and applying tension to such tendon tosecure such tubular structure to such base structure.

Additional exemplary embodiments of the present subject matter mayrelate to a method for constructing a support tower; such methodcomprising providing a foundation; securing a base structure to suchfoundation; placing a transition piece on such base structure; stackinga plurality of tubular structures on top of such transition piece, eachsuch plurality of tubular structures defining a hollow opening, suchplurality of stacked tubular structures including a topmost tubularstructure having a locking mechanism; inserting a mast section havingrespective bottom and top ends through such hollow openings of suchplurality of stacked tubular structures such that such bottom end ofsuch mast section may be adjacent such transition piece; raising suchmast section such that such bottom end of such mast section may beadjacent such locking mechanism of such topmost tubular structure; andengaging such bottom end of such mast section with such lockingmechanism.

Per present variations of the foregoing, such support tower may includea lifting plate, and such lifting plate may include a sealing ringaround an outer perimeter thereof. Also, optionally, such lifting platemay comprise a plurality of pedestals extending from such lifting plate.Such step of inserting such mast section may comprise inserting suchmast section through such hollow openings of such plurality of stackedtubular structures such that such bottom end of such mast section restson top of such pedestals extending from such lifting plate. Such step ofraising such mast section may comprise forcing compressed air into aspace defined between such plurality of stacked tubular structures andsuch lifting plate.

Also, optionally, such locking mechanism of such topmost tubularstructure may comprise an initial ring precast into such topmost tubularstructure, such initial ring comprising a plurality of support teeth;and a toothed ring comprising a plurality of locking teeth. Such bottomend of such mast section may comprise a toothed ring locking mechanism,such toothed ring locking mechanism comprising a plurality of ringteeth. Such plurality of support teeth and such plurality of lockingteeth may comprise a ramped surface to provide frictional engagementwith such ring teeth of such toothed ring locking mechanism. Such stepof engaging such bottom end of such mast section with such lockingmechanism may comprise rotating such mast section such that such ringteeth may be positioned between such support teeth and such lockingteeth.

Variations of present methodology may further include removing suchcompressed air after such lower end of such mast section has beenengaged with such locking mechanism. Variations may further includeproviding an elliptical aperture in such transition piece, and removingsuch lifting plate through such elliptical aperture. Such present methodoptionally may further include mounting a wind turbine to such top endof such mast section, which mast section in certain arrangements maycomprise a cylindrical steel section.

In other present options, such transition piece, such base support, andsuch plurality of stacked tubular structures may be constructedprimarily of concrete. Also, variations of the present method mayfurther include disengaging such bottom end of such mast section fromsuch locking mechanism; and lowering such mast section such that suchmast section may be adjacent such transition piece. Such step oflowering such mast section comprises using compressed air to control therate at which such mast section may be lowered.

Another exemplary embodiment of a present method for constructing asupport tower may comprise constructing a foundation, such foundationhaving an outer perimeter defining a foundational footprint; providing abase structure having respective top and bottom portions, with suchbottom portion thereof secured to such foundation; providing a mastsection having an outer perimeter defining a mast footprint that may besmaller than such foundational footprint; associating a transition piecewith the top portion of such base structure such that such transitionpiece may be placed in a state of horizontal axis compression;associating such mast section with such transition piece such that suchtransition piece may be placed in a state of vertical axis compression;and pouring material in such transition piece to fix such horizontal andvertical compression thereof, such that the transition piece may beassociated with both such base structure and such mast section whilebeing held in biaxial compression.

In the foregoing exemplary method, optionally such foundation may be aring foundation constructed primarily of concrete, or such foundationmay comprise a plurality of peripheral foundation pads constructedprimarily of concrete. Such step of associating such transition piecewith the top portion of such base structure may include positioning aplurality of legs around such transition piece, each of such pluralityof legs constructed primarily of concrete, and respectively having afirst end and a second end; securing such first end of each of suchplurality of legs to such foundation; and securing such second end ofeach of such plurality of legs to such transition piece.

Optionally, still further, such step of associating such transitionpiece with the top portion of such base structure may includepositioning a plurality of staves around such transition piece, each ofsuch staves constructed primarily of concrete, and having a top portionand a bottom portion, the bottom portion of each such stave being widerthan the top portion of each such stave; securing such bottom portion ofeach such stave to such foundation; and securing such top portion ofeach such stave to such transition piece.

Also, such transition piece may be constructed primarily of concrete;and such step of associating such mast section with such transitionpiece may include stacking a plurality of tubular structures constructedprimarily of concrete on top of such transition piece, with such mastconfigured to support a wind turbine generator. Variations of suchmethod may further include extending a plurality of post-tensioningcables through such base structure and such mast section; extending aplurality of post-tensioning cables circumferentially around suchtransition piece; and tensioning such plurality of post-tensioningcables so as to respectively provide horizontal and vertical axescompression to such transition piece.

Still other present alternatives may include constructing a centralfoundation pad; extending a tower structure from such central foundationpad; placing such transition piece on top of such tower structure; andremoving such tower structure after such transition piece may be securedto such base structure. Alternatively, such tower structure may beconstructed primarily of concrete, and/or such tower structure may havea cruciform cross-section or other. Per yet other present variations,the present method may further comprise constructing a centralfoundation pad; extending a tower structure from such central foundationpad, such tower structure having an access ladder; and placing suchtransition piece on top of such tower structure.

Additional objects and advantages of the present subject matter are setforth in, or will be apparent to, those of ordinary skill in the artfrom the detailed description herein. Also, it should be furtherappreciated that modifications and variations to the specificallyillustrated, referred and discussed features and elements hereof may bepracticed in various embodiments and uses of the present subject matterwithout departing from the spirit and scope of the subject matter.Variations may include, but are not limited to, substitution ofequivalent means, features, or steps for those illustrated, referenced,or discussed, and the functional, operational, or positional reversal ofvarious parts, features, steps, or the like.

Still further, it is to be understood that different embodiments, aswell as different presently preferred embodiments, of the presentsubject matter may include various combinations or configurations ofpresently disclosed features, steps, or elements, or their equivalents(including combinations of features, parts, or steps or configurationsthereof not expressly shown in the figures or stated in the detaileddescription of such figures).

Additional embodiments of the present subject matter, not necessarilyexpressed in the summarized section, may include and incorporate variouscombinations of aspects of features, components, or steps referenced inthe summarized objects above, and/or other features, components, orsteps as otherwise discussed in this application. Those of ordinaryskill in the art will better appreciate the features and aspects of suchembodiments, and others, upon review of the remainder of thespecification.

BRIEF DESCRIPTION OF THE DRAWINGS

A full and enabling disclosure of the present subject matter, includingthe best mode thereof, directed to one of ordinary skill in the art, isset forth in the specification, which makes reference to the appendedfigures, in which:

FIG. 1 illustrates an exemplary embodiment of a concrete base support,such as for a windmill, in accordance with the present technology, fullyinstalled and supporting a representative exemplary windmill;

FIG. 2 illustrates an enlarged portion of a lower section of theconcrete base support exemplary embodiment of present FIG. 1,illustrating a temporary support tower and guy wires;

FIG. 3 illustrates an enlarged portion of a lower section of theconcrete base support of present FIG. 1, illustrating lateral supportstructure for the concrete base support legs;

FIG. 4 illustrates an exemplary present foundation plan for an exemplaryconcrete base support in accordance with present technology;

FIG. 5 represents a cross-section view of the exemplary concrete basesupport legs of the present subject matter, taken along section line 5-5of FIG. 1;

FIG. 6 illustrates an exemplary embodiment of an alternate concrete basesupport, such as for a windmill, in accordance with a further embodimentof the present technology;

FIG. 7 illustrates an interior view of the base portion of the exemplarybase support of FIG. 6 illustrating interior integral concrete ribconstruction in accordance with the present technology, seen generallyas from view line 7-7 of present FIG. 6;

FIG. 8 is an enlarged view of a further alternative concrete basesupport in accordance with a yet further embodiment of the presenttechnology;

FIG. 9 is a view similar to that of present FIG. 4, and illustrates anexemplary present foundation plan for a further exemplary concrete basesupport in accordance with present technology;

FIG. 10 is a view similar to that of present FIG. 5, and represents across-section view of yet further exemplary concrete base support legsin accordance with the present technology;

FIG. 11 is a partial, generally side view of an exemplary concreteplatform in accordance with another exemplary embodiment of the presenttechnology;

FIG. 12 is a top view of the exemplary platform of FIG. 11 taken alongview line 12-12 of FIG. 11;

FIG. 13 illustrates a portion of a lower section of the concrete basesupport in accordance with a further exemplary embodiment of presentsubject matter, illustrating a temporary support tower, guy wires, andcircular concrete base support;

FIG. 14 is an enlarge perspective view of the top portion of thetemporary tower illustrated in FIG. 13 with a precast concretetransition piece placed thereon;

FIG. 15 illustrates the placement of a first pair of staves positionedin balanced relationship on opposite sides of the transition piece;

FIG. 16 is a top view taken from line 16-16 of FIG. 15 showing acompleted skirted base structure;

FIG. 17 illustrates a top perspective view of the precast transitionpiece with all stays in place and banded around with a corrugated metalcollar;

FIG. 18 illustrates a view similar to that of FIG. 17 but including asealing plate that forms a portion of a tower hydraulic liftingmechanism;

FIG. 19 illustrates a view similar to that of FIG. 18 but including atower lifting plate;

FIG. 20 illustrates a view similar to that of FIG. 19 and includingillustration of a first precast concrete tower section shown partiallyin phantom to better illustrate aspects of the internal construction;

FIG. 21 illustrates coupling of ducts within the stays and precastconcrete tower section to provide passageways for securing strands;

FIG. 22 illustrates sealing and circumferential clamping of the jointbetween the first section of precast concrete tower portion and theprecast transition piece;

FIG. 23 illustrates, partially in phantom, the stacking of additionalprecast concrete tower sections and the insertion into the stackedconcrete sections of a steel tower section;

FIGS. 24-27 illustrate several stages in the construction of a toothedlocking ring atop the topmost precast concrete tower section;

FIG. 28 illustrates an exemplary tower in accordance with presenttechnology in a fully extended position and supporting a wind generator;

FIG. 29 illustrates a cross section segment of a locking ring mechanismprior to rotation into a locked position;

FIG. 30 illustrates partially in phantom an access hole through theprecast concrete transition piece after removal of the lifting plateused to raise the steel tower portion into position;

FIG. 31 illustrates a completed tower construction supporting a windgenerator but omitting the normally accompanying turbine blade assembly;

FIG. 32 is a cross section of a portion of a precast base includingballast fill and stave anchoring features in accordance with certainexemplary embodiments of the present technology;

FIG. 33 illustrates a cross section of an alternate configuration of theprecast base structure that is identical to that of FIG. 32 except thatthe upstanding wall section has been replaced with a separatedcorrugated metal structure in accordance with certain other exemplaryembodiments of the present technology;

FIG. 34 illustrates in cross section an alternate arrangement forforming the transition piece using a precast concrete collar;

FIG. 35 is a cross sectional view of the assembled locking ringmechanism shown in portions in FIGS. 24-27 and 29;

FIG. 36 illustrates the optional use of lateral bracing during erectionof the steel tower portion;

FIG. 37 illustrates preliminary construction of a multi-stage tower basefor use with larger capacity turbines and higher towers;

FIG. 38 illustrates an exemplary implementation of “U” shaped tendons toprovide multiple joint crossing and enhanced stave retention; and

FIG. 39 illustrates a plan view of a support tower in accordance with afurther exemplary alternative embodiment of the present subject matter.

Repeat use of reference characters throughout the present specificationand appended drawings is intended to represent same or analogousfeatures, elements, or steps of the present subject matter.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

As discussed in the Summary of the Invention section, the presentsubject matter is particularly concerned with apparatus andcorresponding methodology for providing base supports, such as comprisedat least in part of precast concrete, and such as for windmills andwind-driven power generators, or other apparatuses.

Selected combinations of aspects of the disclosed technology correspondto a plurality of different embodiments of the present subject matter.It should be noted that each of the exemplary embodiments presented anddiscussed herein should not insinuate limitations of the present subjectmatter. Features or steps illustrated or described as part of oneembodiment may be used in combination with aspects of another embodimentto yield yet further embodiments. Additionally, certain features may beinterchanged with similar devices or features not expressly mentionedwhich perform the same or similar function.

Reference will now be made in detail to the presently preferredembodiments of the subject concrete base support, shown for example, insupport of representative exemplary windmills. With reference to thedrawings, FIG. 1 illustrates an exemplary embodiment of a concrete basesupport generally 100, such as for a windmill, in accordance with thepresent technology, illustrated as fully installed and supporting arepresentative generator generally 120 and accompanying turbine bladeassembly generally 122. Those of ordinary skill in the art willappreciate that particular internal details regarding such generator 120and turbine blade assembly 122 form no particular aspects of the presentsubject matter, wherefore further additional detailed discussion of suchdevices is not required for a complete understanding of the presentsubject matter.

Concrete base support 100 corresponds to a number or plurality ofsections, all of which are made of concrete in various forms, so as toprovide particular capabilities as required for desired support ofgenerator 120 and turbine blade assembly 122.

As may be seen from FIG. 1, concrete base support 100 corresponds to aleg section comprising, in an exemplary configuration, such as eightlegs representatively illustrated by leg 114. Various numbers of legsmay be practiced in accordance with the present subject matter. Each ofsuch legs 114 rests on an individual foundation block generally 116, asis described more fully hereinbelow with reference to present FIG. 4.Further, each such leg generally 114 is preferably inserted into one ofa corresponding number of mating holes 117 in a platform 112. In anexemplary configuration, platform 112 may be constructed of reinforcedconcrete, may be circular in shape, may have a diameter of twenty sixfeet and may be four feet thick. Each leg 114 may measure four feet byfour feet and have eight inch thick walls. The leg portion is assembledwith the assistance of temporary structure, as is described hereinbelowwith reference to FIG. 2.

Portions 102, 104, 106, and 108 of concrete base support 100 preferablyvary in size as illustrated in and represented by FIG. 1, and alsopreferably are constructed with varying concrete compositions. Portion102 of concrete base support 100 corresponds to a number of stackedreinforced prestressed concrete cylinders representatively illustratedas cylinders 132, 134, 146. Each cylinder 132, 134, 136 may also includereinforcing bars (rebars), for example, common steel bar, as is commonlyused in reinforced concrete. Further, it should be noted that while thepresent description may speak of concrete cylinders, such descriptiondoes not necessarily mean that the outer and/or inner shape is circular.In fact the concrete cylinders constructed in accordance with thepresent technology may correspond to cylindrical, octagonal, hexagonal,or any other outside and/or inside surface formation or combinationsthereof.

Each of the concrete cylinders 132, 134, 136 in section 102 of concretebase support generally 100 preferably is substantially the same size andsimilarly constructed of reinforced prestressed concrete. Each of suchcylinders also is preferably constructed for mating assembly such thatthe top of one cylinder is shaped to mate with the bottom of the next,i.e., adjacent, cylinder. As the cylinders 132, 134, 136 are stacked,each preferably is adhesively secured together using, for example, anepoxy or grout. In an exemplary configuration, twenty cylinders may bestacked together to form section 102 of concrete base support 100 whereeach cylinder 132, 134, 136 may be six feet tall thereby producing asection 102 which is one hundred twenty feet tall.

Following assembly of section 102 of concrete base support 100, atransition ring or cylinder 104 is placed on the top cylinder of portion102. As may be seen from the representations of present FIG. 1, suchtransition cylinder 104 preferably varies in diameter from a diametercorresponding to the diameter of section 102 to a smaller diametermatching the diameter of the cylinders forming section 106. In anexemplary configuration, transition cylinder 104 may have a midpointdiameter of thirteen feet and have an eighteen inch thick wall.Transition cylinder 104 as well as each of the cylinders in portion 106of concrete base support 100 representatively illustrated as cylinders142, 144, 146 are formed of ultra high performance fiber reinforcedconcrete. In an exemplary configuration, the ultra high performancefiber reinforced concrete may employ steel fiber as the fiber componentof the concrete. In other embodiments, other fibers comprise of othermaterials, now known or later developed, may be utilized.

As previously referenced, each cylinder of section 106, representativelyillustrated as cylinders 142, 144, 146, of concrete base supportgenerally 100 is constructed from ultra high performance fiberreinforced concrete and may employ steel fiber for reinforcement. In anexemplary configuration, seven cylinders each fifteen feet tall may bestacked to produce a section 106 which is one hundred five feet tall.

Following assembly of section 106 of concrete base support 100, anadditional cylinder 108 preferably is affixed to the top most cylinderof portion 106. Top most cylinder 108 has a bottom portion configured tomate with the top cylinder of portion 106 and a top surface thatprovides a mounting surface for representative generator 120. Inaddition, there is provided an anchoring ring to secure one end of apost tensioning cable assembly that extends per the present subjectmatter from such anchoring ring to a corresponding anchor at platform112.

Once each of the various cylinders have been stacked and respectivelyglued into place, a cable 110 is passed through the hollow center ofeach of the stacked cylinders, secured at the anchor ring at the top ofthe string and at the anchor associated with platform 112 (i.e., at thebottom of the string) and tightened, thereby providing an internalvertical post tensioning system to assist in securing each of therespective cylinders.

With reference to present FIG. 2, there is illustrated an enlargedportion of a lower section generally 200 of the concrete base support100 illustrating a temporary support tower 210 and guy wires 224, 226employed to support platform 112 during assembly of the concrete basesupport 100. As may be seen from such FIG. 2, temporary tower 210 restson its own foundation blocks, representatively illustrated as blocks 222and 224, and which may be placed below grade along with tower leg 114support blocks, representatively 116. Further, guy wires 224, 226 may besecured to foundation blocks 116 and to the top of temporary tower 210for added stability. Those of ordinary skill in the art will appreciatefrom the disclosure herewith that the components variously referencedherein as “temporary” are intended to be removed once the remainder ofthe presently described structure is assembled at a designated area. Onthe other hand, certain “temporary” components may be at least partiallyretained. For example, tower 210, or portions thereof, might be retainedto facilitate access to the upper portions of an erected tower and toserve as support structure for power lines, for example, coupled to thegenerator 120 or other items requiring physical support.

With reference to FIG. 3, there is illustrated an enlarged portion of alower section 200 of the concrete base support 100 illustrating lateralsupport structure 302 for the concrete base support legs 114. Lateralsupport structure 302 may be constructed of reinforced concrete or steeland may be secured to legs 114 in any suitable manner.

With reference to FIG. 4, there is illustrated an exemplary foundationplan 400 for the concrete base support 100 in accordance with presenttechnology. As illustrated in FIG. 4, eight foundation pads,representatively pads 402, 404, 406, 408 may be provided. Each of thepads 402, 404, 406, 408 is coupled to a central pad 410 by way oftension tie members 412, 414, 416, 418. Coupling pads 402, 404, 406 and408 to central pad 410 enhances the stability of the foundation plan400. Leg engaging supports representatively illustrated as supports 422,424, 426, 428 are associated with each foundation pad 402, 404, 406,408. In an exemplary configuration, pads 402, 404, 406, 408, 410 mayeach correspond to fifteen by fifteen foot concrete block each threefeet thick. Tensioning tie members 412, 414, 416, 418 may eachcorrespond to eighteen inch by eighteen inch concrete sections.Tensioning tie members 412, 414, 416, and 418 may also include ametallic tendon extending through the tensioning tie members 412, 414,416, and 418 for further support.

With reference now to FIG. 5, there is illustrated a cross-section viewof the concrete base support legs 114 taken along section line 5-5 ofFIG. 1. Also visible are the eight foundation pads representativelyillustrated as pads 502, 504, 506, 508.

Referring now to FIGS. 6 and 7, an exemplary embodiment of analternative concrete base support features 610, such as for a windmill,in accordance with a further embodiments of the present technology andemploying ribbed concrete panel construction is described. As may beseen in FIG. 6, a concrete base and tower structure generally 600 may beconstructed by supporting pre-formed concrete blocks representativelyillustrated as blocks 620 cast with integral ribs 704 (see FIG. 7).Elements 702 represent concentric elements of support which are achievedwith such present exemplary embodiment.

A generally circular concrete foundation 622 replaces the plurality ofconcrete pads 402, 404, 406, 408, 502, 504, 506, 508 illustrated in theembodiment represented in FIGS. 4 and 5, and support a steel skeletalstructure over which a plurality of blocks 620 are placed. The exemplarybase 610 thus formed supports a tower section composed of a plurality ofgenerally circular sections 630, 632 stacked upon each other and allsupported by base 610.

With reference to present FIG. 8 there is illustrated an enlarged viewof a further alternative concrete base support generally 800 inaccordance with a yet further exemplary embodiment of the presenttechnology. Concrete base support 800 provides a series of respectivelegs 814 (in this instance, eight such legs) each resting at one endthereof on a circular concrete foundation 816. The other end of each ofsuch exemplary eight legs 814 supports exemplary platform 812, whichthen in turn supports a representative tower section generally 820.Also, intermediate respective brace supports, generally 818, may beprovided between respective legs 814, as illustrated. It should beappreciated that while eight legs are illustrated, such number of legsis an exemplary representation of the present embodiment, and suchnumber of legs may vary as required based on particular needs related totower support requirements.

In addition to the eight legs 814 illustrated in FIG. 8, additional legscentrally positioned with respect to the illustrated legs 814 may alsobe provided but are not illustrated in FIG. 8, simply in order to avoidunnecessary clutter in the drawing. The positioning of such legs may beseen, however, from FIGS. 9 and 10, and in particular from FIG. 10,where both legs 814 and a group of four centrally located legs 1014 areillustrated. Also illustrated in FIGS. 9 and 10 are additional concretepads 1016 positioned to support centrally located legs 1014. As withlegs 814, it should be appreciated that the number of centrallypositioned legs may vary from that illustrated to accommodate particulartower support requirements for a given embodiment of the present subjectmatter.

With reference to FIGS. 11 and 12, there is illustrated an exemplaryrepresentative platform 1110 configured so as to be supported by thepreviously illustrated legs 814 and 1014, and so as to support thereonprecast concrete tubular tower sections representatively illustrated assection 1120. Platform 1110 generally corresponds to a precast portion1112 having a generally U-shaped cross section and including a number ofprecast column penetrations 1114 provided for insertion of legs 814,1014. In one exemplary configuration, precast platform 1110 may have,for example, an overall diameter of 26 feet, a height of 4 feet, and acentral open aperture (unnumbered) of 8 feet. Those of ordinary skill inthe art will appreciate that such dimensions are exemplary dimensionsonly and may vary depending of particular tower support requirements ofa given embodiment.

Platform 1110, when completed during assembly of the tower structure,also corresponds to a quantity of field poured concrete elements 1116,which fill the precast portion 1112, secure legs 814, 1014 in position,and function as a support for precast concrete tubular tower sections1120.

With reference now to FIGS. 13-31, a further exemplary embodiment of thepresent base support for wind-driven power generators will be described.As may be seen in FIG. 13, a concrete base support and temporary towerconstruction may be seen that is similar, in many respects, to thepreviously described embodiment. As illustrated in FIG. 13, there isprovided a concrete base 1316 including embedded therein a number ofanchor elements 1318. Concrete base 1316 may be poured in place andrequires minimal or nor excavation. In an exemplary configuration,concrete base 1316 may be sixty feet in diameter and may be provided asa shallow foundation extending just below the frost line, perhaps two tothree feet in depth.

A second concrete base support 1330 may be rectangular and centrallypositioned within an open space within the circular concrete base 1316.Concrete base support 1330 is large enough to provide support fortemporary tower 1310 which may be held in position by one or more guywires 1324, 1326. It should be appreciated that while the presentconstruction permits removal of tower 1310, such tower may,nevertheless, be retained for other purposes including providing supportfor conductive cables associated with the wind generator, for access tothe central portion of the rower above transition piece 1412 or forother purposes not directly related to the tower construction.

Referring now to FIG. 14, there is seen an enlarged perspective view ofthe top portion of temporary tower 1310 illustrated in FIG. 14 with aprecast concrete transition piece 1412 placed thereon. Transition piece1412 may be raised into position using a crane or other suitablemechanisms and is placed on flat pads 1420, 1422, 1424 secured to thetops of vertical sections of tower 1310. Transition piece 1412 simplesits in place in is more securely positioned by placement of staves andother securing devices as will be explained more fully later.

Transition piece 1412 is constructed with as a multifaceted precastconcrete construction to include a number of facets 1432, 1434, 1436,where the number of facets is equal to the number of staves to bepositioned about the perimeter of the transition piece 1412. It shouldfurther be noticed that an elliptical aperture 1440 is provided throughthe central portion of transition piece 1412 and provides a passage waythrough transition piece 1412. Elliptical aperture 1440 provides for theremoval of an elongated sealing plate as will be more fully describedlater.

With reference now to FIGS. 15 and 16, it will be seen that a number ofpairs of staves 1520, 1522 are positioned with a wider base portion 1540resting on concrete base 1516 and a narrower top portion 1542 simplyleaning against a correspondingly sized facet 1536 of transition piece1512. Base portion 1540 may be secure against radial and lateralmovement by attachment to one or more anchor elements 1518. FIG. 16illustrates a top view taken from line 16-16 of FIG. 15 showing acompleted skirted base structure including concrete base 1516, pluralpairs of staves 1520, 1522 positioned at top portions thereof in contactwith facets of transition piece 1512. Also illustrated is ellipticalaperture 1640 exposing portions of temporary tower 1610.

FIG. 17 illustrates a top perspective view of the precast transitionpiece 1712 with all staves 1720, 1722 in place and banded around with acorrugated metal collar 1752. In an alternative configuration,corrugated metal collar 1752 may be replaced with a precast concretecollar 1752′ as illustrated in FIG. 34. Elliptical aperture 1740 is alsoillustrated providing a passageway through transition piece 1712. Anumber of additional feature of transition piece 1712 are more clearlyillustrated in FIG. 17 including a number of conduits 1762, 1764, 1766,1768, the ends of which may be seen exposed on the ends of staves 1720,1722. Conduits 1762, 1764, 1766, 1768 extend, in certain embodiments,through the length of staves 1720, 1722. In certain other embodiments,conduits 1762, 1764, 1766, 1768 may extend only a certain way down thelength of staves 1720, 1722 to then turn and join with other conduits toform a U-shaped conduit from the top portion the individual stave toemerge as separate legs of the U-shape in the same or, possibly adjacentstave. In assembled form, the conduits provide a passage way for ametallic strand that may be threaded through the conduits to providestrengthened assembly of the various tower components. As will beexplained further later, the metallic strands may be extended throughfurther conduits provided in further tower portions to further assist insecuring the tower components together.

Referring to FIG. 18, it will be noticed that the illustration issubstantially identical to that of FIG. 17 with the addition of ametallic plate 1842 covering elliptical aperture 1740 (FIG. 17).Metallic plate 1842 may be constructed of steel and has provided on thetop portion thereof a number of standoffs 1844, 1846, 1848 that areprovided as support for a lifting plate to be described later. It shouldbe noticed that metallic plate 1842 is constructed to have a length anda width such that the width is narrower than the longer length of theelliptical aperture 1740 yet the width is wider than the narrower widthof the elliptical aperture 1740. In this way, metallic plate 1842 may beturned so that it will pass through elliptical aperture 1740 for removalas an optional final portion of the tower erection process.

FIG. 19 illustrates a view similar to that of FIG. 18 and furtherillustrates a tower lifting plate 1902. Positioned around the perimeterof lifting plate 1902 are a number of pedestals 1904, 1906, 1908.Pedestals 1904, 1906, 1908 generally correspond to portions of an I-beamand include a flat top surface configured to interface with end edge ofa steel cylindrical tower portion and to lift the steel cylindricaltower portion in place using air pressure as will be described morefully later. In conjunction with the object of lifting the steelcylindrical tower portion using air pressure, a sealing ring 1910 isprovided around the outer perimeter of lifting plate 1902 that functionsin combination with the inner surface of one or more precast concretetower sections to provide a substantially air tight seal.

With reference to FIG. 20, there is illustrated a view similar to thatof FIG. 19 and further illustrating a first precast concrete towersection 2002 shown partially in phantom to better illustrate aspects ofthe internal construction. As will be noticed from FIG. 20, there are anumber of conduits 2004, 2006, 2008 provided within the wall of theprecast concrete tower section 2002. Conduits 2004, 2006, 2008 arepositioned to cooperate with conduits 1762, 1764, 1766, 1768incorporated into staves 1720, 1722 (FIG. 17) and provide guides throughwhich metallic threads may be passed to assist in securing the varioustower components together. As may be seen most clearly in FIG. 20,precast concrete tower portion 2002 is sized to fit over lifting plate1902 and is supported in place by a number of corbels or support blocks1922, 1924 integrally incorporated into transition piece 1912 andradially extending from the perimeter thereof, as best seen in FIG. 19.

With reference now to FIG. 21 there is illustrated a first precastconcrete tower section 2102 sitting in place on top of transition piece2112. Coupling ducts 2130, 2132, 2134, 2136, 2138 are installed tocouple ducts within the staves 2120, 2122 and precast concrete towersection 2102 to provide passageways for securing metallic strands.Referring now to FIG. 22, it will be seen that following placement ofcoupling ducts 2130, 2132, 2134, 2136, 2138, the space enclosed bycorrugated metal band 2152 (FIG. 21) is filled with concrete 2202 andsurrounded by a number of circumferential clamps 2240, 2242, 2244, 2246configured to place the poured concrete filled corrugated metal band2152 in compression.

With reference now to FIG. 23, it will be seen that a number of precastconcrete cylindrical tower sections 2302, 2304, 2306 may be stacked oneupon another to extend the height of the tower. Each section may includeconduits as previously illustrated as conduits 2004, 2006, 2008 in FIG.20 and shown in phantom in tower section 2306 of FIG. 23. It should beappreciated that while three precast concrete sections 2302, 2304, 2306are illustrated in FIG. 23, such number of sections is exemplary only.In practice the number of sections may generally vary from one to fourdepending on desire final height. It should also be noted that while thepresent disclosure is directed primarily to the provision of precastconcrete tower sections, such is not a limitation of the present subjectmatter in that these sections may be constructed of other materialsincluding steel.

After the desire number of precast concrete tower sections have beenstacked, a final cylindrical steel section 2308 is positioned within thestacked concrete sections and lowered so as to contact the pluralpedestals 1904, 1906, 1908 secured to the upper surface of lifting plate1902 (FIG. 19). Cylindrical steel section 2308 includes a ringed toothengagement mechanism (not separately illustrated) on the lower portionof cylindrical steel section 2308 so that when cylindrical steel section2308 is raised and later rotated the mechanism meshes with a lockingtooth mechanism installed on the top portion of the top concrete towersection as will be explained more fully with reference to FIGS. 24-27.

First as may be seen in FIG. 24, an initial ring 2442, is precast intothe top cylindrical precast concrete section 2406. Ring 2442 includes anumber of support teeth 2452, 2454, 2456, 2458 around the centralportion thereof. Toothed ring 2542 (FIG. 25), corresponding to toothedring 2442 of FIG. 24, as may be better observed in an exposed view, hasprovided thereon extending radially toward the center of ring 2544 aplurality of teeth 2552, 2554, 2556, 2558 corresponding to the teeth ontoothed ring 2442 of FIG. 24. A spacer ring 2646 (FIG. 26) is thenplaced over toothed ring 2542. As seen in FIG. 26, spacer ring 2646 isnarrow enough to leave exposed at least the tooth portions 2552, 2554,2556, 2558 of ring 2544. Lastly, as illustrated in FIG. 27, anadditional ring 2748 is placed over spacer ring 2646. The various ringsmay all be made of steel and the teeth associated with toothed ring 2542may be machined to have a slight ramped surface so that the spaceprovided between the surface of ring 2748 facing the plurality of teethassociated with ring 2544 provides frictional engagement of thecorresponding teeth on the ringed tooth engagement mechanism secured tosteel cylindrical tower section 2308 (FIG. 23).

With reference now to FIG. 27, it will be noticed that a number ofsecuring devices 2752, 2754, 2756, 2758 are provided that secure theends of metallic strands threaded through the previously discussedconduits provided in the precast concrete tower sections as well as thetransition piece supporting staves.

With brief reference now to FIG. 35, there is illustrated a crosssectional view of the assembled locking ring mechanism shown in portionsin FIGS. 24-27. The locking ring mechanism corresponds to a lowertoothed ring 2542 which is precast into the upper portion of concretetower portion 3502. A number of corbels 3522 extend from the innersurface of the concrete tower portion 3502 to assist in supportingtoothed ring 2542. Spacer ring 2646 is positioned on top of toothed ring2542. An additional ring 2748 is placed over spacer ring 2646 andsecured in place by a number of securing device represented by securingdevice 3556 which also secures the ends of metallic strands aspreviously noted. Steel tower section 2308 has secured to the lower endthereof toothed ring 2544. In an exemplary configuration, toothed ring2544 may be secured to the lower portion of steel tower section 2308 bywelds 3570, 3572. An additional steel band 3574 may be provided forreinforcement of the joint.

Referring now to FIG. 28, it will be seen that a wind powered generator2800 may be mounted to the top of cylindrical steel section 2808 and thecombination raised to a final operating position by forcing compressedair into the space between the end of the lower most precast concretetower section 2806 and the lifting plate 2802. Those of ordinary skillin the art will appreciate that the normally required wind turbineblades associated with wind generator 2800 may be attached to thegenerator prior to raising the assembly. Such turbine blades are notpresently illustrated.

With reference now to FIG. 29, there is illustrated a cross sectionsegment of a locking ring mechanism prior to rotation into a lockedposition. As may be seen, the locking mechanism corresponds to aplurality of teeth 2552, 2554 and to a further plurality of teeth 2972,2974, 2976 associated with the previously mentioned ringed toothengagement mechanism associated with steel cylindrical tower section2808. As steel cylindrical tower section 2808 is raised by applicationof air pressure as previously noted, the steel cylindrical tower section2802 is rotated to align teeth 2552, 2554 to pass between teeth 2972,2974, 2976. The entire cylindrical tower section 2802 is then rotated sothat teeth 2552, 2554 are secured by the camming effect of teeth 2972,2974, 2976 and the retaining friction obtained there between and theupper most ring 2748.

After rotation and locking of the cylindrical tower section 2808, airpressure within the assembled tower is released and lifting plate 1902returns to its original position at rest on top of transition piece 1912as seen in FIG. 19. At this time lifting plate 1902 and metallic plate1842 (FIG. 18) may be removed to provide access to the internalstructure of the assembled tower. Alternatively, these components may beleft in place in the event that the steel cylindrical tower section andattached wind generator may need to be lowered for repair, replacement,or other maintenance. If these components are to be left in place,access panels may be provided as necessary in metallic plate 1842 andlifting plate 1902 as required. FIG. 30 illustrates a condition wheremetallic plate 1842 and lifting plate 1902 have been removed while FIG.31 illustrates the assembled tower in its fully extended position.

With reference now to FIG. 32 there is illustrated a cross section of aportion of a precast concrete base 3216 including ballast fill 3220,3222 and stave anchoring features 3230 in accordance with certainexemplary embodiments of the present technology. As illustrated in FIG.32, a feature of the present subject matter resides in the ability ofthe base support to be provided with minimal excavation requirements. Assuch, relatively shallow foundations placed just below the frost linefor the particular tower location. Generally this will be two to threefeet deep. This feature of being able to provide a poured in placecircular strip footing as illustrated in FIG. 13 may be extended to aprecast concrete sectionalized base as illustrated in FIG. 32. As shownin FIG. 32, base 3216 is provided with a flat lower portion 3240 andincludes a radially outward outer upstanding wall 3242 and includesintegral formed stave portions 3244. Integral stave portions 3244include anchoring features 3230 corresponding to the metallic strandreceiving conduits previously discussed with respect to FIG. 17 andconduits 1762, 1764, 1766, 1768. A plurality of sections correspondingto base 3216 may be placed in a circular trench containing compactedmaterial 3250 which, in an exemplary configuration, may be one to sixfeet thick. Each of the plurality of sections may be secured together bymetallic threads 3266 threaded through integral conduits 3262, 3264 andthe entire assembly may be provided with additional ballast 3220, 3222in the form of, for example, a stone fill. FIG. 33 illustrates analternate configuration of the precast base structure that is identicalin every way to that of FIG. 32 except that upstanding wall section 3242has been replaced with a separated corrugated metal structure 3342 and aseries of post tensioning bands 3352 which function to retain ballast.

Referring now to FIG. 36, there is illustrated the optional use oftemporary lateral bracing during erection of the steel tower portion. Asmay be seen from FIG. 36, a plurality of steel braces 3682, 3684, 3686may be temporarily, or even permanently, secured to ring 3648 atopconcrete tower portion 3602 to function as bracing for steel towerportion 3608 during the erection process. Steel braces 3682, 3684, 3686may be left in place to provide bracing during lowering of steel towerportion 3608 in a manner similar to the choice of leaving in placelifting plate 1902 (FIG. 19) and metallic plate 1842 (FIG. 18). Atopeach steel brace 3682, 3684, 3686 may be provide a mechanism generallyillustrated as a roller assembly 3692, 3694 but which may correspond toother mechanisms that more easily provide support for movement in bothvertical and horizontal directions to accommodate rotation of steeltower portion 3608 to the final tooth locking position. Further,unillustrated spring loading mechanisms may be provided in associationwith each of the steel braces 3682, 3684, 3686 to insure supportivecontact to the steel tower section 3608.

Referring now to FIG. 37, there is illustrated a multi-stage tower basegenerally 3700 designed to provide support, for example, for largercapacity turbines positioned at heights higher than single stage towersupports. As seen in FIG. 37, a top portion generally 3702 ofmulti-stage tower base 3700 is constructed in a manner similar to thatshown and described in conjunction with FIGS. 15 and 16. Thus, in FIG.37 it will be seen that a number of pairs of staves 3720, 3722 arepositioned with a wider base portion 3740 resting on concrete base 3716and a narrower top portion 3742 simply leaning against a correspondinglysized facet 3736 of transition piece 3712.

In a manner similar to that illustrated in FIG. 16, a completed topportion 3702 of skirted tower base 3700 includes concrete base 3716 andplural pairs of staves similar to staves 3720, 3722 positioned with topportions thereof in contact with other facets of transition piece 3712and bottom portions resting on concrete base 3716. In exemplaryconfigurations, concrete base portion 3716 may be either pre-cast orcast in place. Thus, concrete base 3716 may be considered a lowertransition piece in some embodiments in which transition piece 3712 isan upper transition piece.

A lower portion generally 3704 of multi-stage tower base 3700 is similarto the top portion 3702 and supports concrete base 3716 by way of pluralpairs of staves exemplarily illustrated as staves 3744, 3746. A centralsupporting tower 3710 rests on concrete support 3752 and extends fromconcrete support 3752, through a central opening 3718 in concrete base3716, and upward to support transition piece 3712. As in previousembodiments, central tower 3710 may correspond to a temporary orpermanent structure.

In an exemplary embodiment, the upper portion 3702 of tower base 3700may incorporate about six pairs or twelve staves while lower portion3704 may incorporate nine or ten pairs or eighteen to twenty staves. Ofcourse, different numbers of staves may be incorporated in both theupper and lower portions of tower base 3700 depending on constructionrequirements for a particular embodiment, or depending on particulardesign criteria for given customers. Also, one or more of such stavesmay be formed of plural subcomponents, as understood by those ofordinary skill in the art from, for example, the collective stavestructure of FIG. 37 and the multi-block structure of the concrete baseof FIG. 6.

With reference now to FIG. 38, there is illustrated an exemplaryimplementation of “U” shaped tendons to provide multiple joint crossingand enhanced stave retention. The illustrated tower section correspondsto a number of staves 3822, 3824, 3826 configured to support a concretering generally 3828, which staves are secured together at least in partby a number of individual tendons 3810, 3812, 3814, 3816. The assemblyis designed to support a cylindrical steel tube section 3802 with theassistance of tube support structure 3804. An upper portion of steeltube 3802 (not shown) may be configured as well understood by those ofordinary skill in the art to support a wind turbine.

Staves 3822, 3824, 3826 abut each other at joints 3832, 3834, and areheld in place by tendons 3810, 3812, 3814, 3816. In accordance withpresent technology, tendons 3810, 3812, 3814, 3816 are configured topass through tubes cast into concrete ring 3828 and each of the staves3810, 3812, 3814, 3816 as “U” shaped formations crossing adjacent stavesat multiple locations generally designated along lines X, Y, and Z.

An exemplary tendon 3842 is secured at the top of concrete ring 3828 andpasses through tubes embedded in concrete ring 3828. Such exemplarytendon 3842 then passes through similar tubes embedded in stave 3822until it reaches a point 3844 where the tendon is divided into a firstportion that loops around to point 3854 and exits at point 3852 again atthe top of concrete ring 3828. A second portion of tendon 3842 continueson to point 3846 where it again is split, with one portion going topoint 3856 and a second portion going on to point 3848. The tendonportion advancing to point 3848 passes through tubes embedded in bothstaves 3822 and 3824, and then joins up with the remaining portions,including those that pass through tubes in both staves 3822 and 3824between points 3846 to 3856 and 3844 to 3854. Similar separating andrejoining of the several other tendons occurs with all of the individualstaves.

In accordance with present technology, such separating of the individualtendons into multiple portions provides for enhanced coupling of thestaves at multiple points along joints 3832, 3824. It should beappreciated that while present discussion describes tendons separatinginto three portions, each coupling adjacent staves at three separatepoints, the present subject matter is not so limited; therefore, thetendons may be separated into three, four or five or more portions, eachcrossing at separate points to secure plural staves.

With reference now to FIG. 39, there is illustrated an alternativeexemplary support tower generally 3910 employed to support the upperportions of an erected tower. The support tower 3910 may be used inplace of the temporary support tower 210 illustrated in FIG. 2. Supporttower 3910 may be constructed of concrete or any other materials,including steel. As illustrated, support tower 3910 comprises a concretecolumn having a cruciform cross-section that includes legs 3912, 3914,3916, and 3918. Those of ordinary skill in the art will appreciate fromthe disclosure herewith that the cross-section of the column supporttower 3910 may have any shape suitable for providing supplementalsupport to the erected tower. For example, the column support tower 3910may have a hollow cylindrical cross-section. The column support tower3910 may be retained after construction of the tower is completed tofacilitate access to the upper portions of the erected tower and toserve as a supplemental support structure for the erected tower andother items requiring physical support. An exemplary access ladder 3920is attached to the column support tower 3910 by mounting brackets 3922.Guy wires and/or compression braces may be secured to the legs 3912,3914, 3916, and 3918 of the support tower 3910 for added stability.

While the present subject matter has been described in detail withrespect to specific embodiments thereof, it will be appreciated thatthose skilled in the art, upon attaining an understanding of theforegoing, may readily produce alterations to, variations of, andequivalents to such embodiments. Accordingly, the scope of the presentdisclosure is by way of example rather than by way of limitation, andthe subject disclosure does not preclude inclusion of suchmodifications, variations, and/or additions to the present subjectmatter (either concerning apparatus or methodology) as would be readilyapparent to one of ordinary skill in the art.

What is claimed is:
 1. A base structure for a support tower, comprising:a ring foundation pad; a transition piece disposed above said ringfoundation pad; a plurality of lower staves positioned around saidtransition piece, each said lower stave respectively comprising a topportion and a bottom portion, the bottom portion of each said lowerstave being wider than the top portion of each said lower stave, thebottom portion of each said lower stave respectively secured to saidring foundation pad, the top portion of each said lower staverespectively secured to said transition piece; and a plurality of upperstaves, each said upper stave respectively comprising a top portion anda bottom portion, the bottom portion of each said upper stave beingwider than the top portion of each said upper stave, the bottom portionof each said upper stave being secured to said transition piece.
 2. Thebase structure of claim 1, wherein said transition piece comprises acentral ring structure.
 3. The base structure of claim 1, furthercomprising an upper transition piece disposed above said transitionpiece.
 4. The base structure of claim 3, wherein said plurality of upperstaves are positioned around said upper transition piece.
 5. The basestructure of claim 3, wherein said top portion of each said upper staveis secured to said upper transition piece.
 6. The base structure ofclaim 3, further comprising: a central foundation pad situated withinsaid ring foundation pad; and a tower structure supported on saidcentral foundation pad, with said upper transition piece positioned ontop of said tower structure.
 7. The base structure of claim 3, whereinsaid upper transition piece further defines an aperture formed through acentral portion thereof.
 8. The base structure of claim 7, wherein saidaperture has an elliptical shape.
 9. The base structure of claim 3,wherein said upper transition piece includes a plurality of facetsaround a perimeter thereof, and wherein said top portion of each saidupper stave is configured to be respectively adhered to one of saidplurality of facets.
 10. The base structure of claim 1, wherein saidplurality of lower staves, said plurality of upper staves, and saidtransition piece are constructed primarily of concrete.
 11. The basestructure of claim 1, further comprising a plurality of anchor elements,located on said ring foundation pad, and respectively configured tosecure one of said staves against radial and lateral movement.
 12. Thebase structure of claim 1, wherein said plurality of lower staves form aconical skirt, said conical skirt operating to distribute a tower loadto said ring foundation pad.
 13. The base structure of claim 1, whereinat least some of said plurality of lower staves and plurality of upperstaves comprise plural subcomponents.
 14. The base structure of claim 1,further comprising a plurality of external ballasts, said externalballasts configured to add additional dead load to said ring foundationpad.